Control of Rotary Series Elastic Actuator for Ideal Force-Mode Actuation in Human–Robot Interaction Applications

Kong, Kyoungchul; Bae, Joonbum; Tomizuka, Masayoshi

doi:10.1109/tmech.2008.2004561

Cited by 373 publications

(197 citation statements)

References 23 publications

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“…PMA have intrinsic elasticity (compliance) which can be used in providing compliant actuation [41]. Several robotic orthoses powered by PMA have been developed for the gait training of neurologically impaired subjects [38,40,[42][43][44][45][46][47].…”

Section: Assist-as-needed Control Of An Intrinsically Compliant Robotmentioning

confidence: 99%

Assist-as-Needed Control of an Intrinsically Compliant Robotic Gait Training Orthosis

Hussain

Jamwal

Ghayesh

et al. 2017

IEEE Trans. Ind. Electron.

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Abstract-It is a common hypothesis in the field of robot assisted gait rehabilitation that the active involvement and voluntary participation of neurologically impaired subjects in the robotic gait training process may enhance the outcomes of such therapy. An adaptive seamless assist-as-needed (AAN) control scheme was developed for the robotic gait training. The AAN control scheme learns in real time the disability level of human subjects based on the trajectory tracking errors and adapts the robotic assistance accordingly. The overall AAN control architecture works on the basis of a robust adaptive control approach. The performance of seamless AAN control scheme was evaluated during treadmill training with a compliant robotic orthosis having 6-degrees of freedom (DOF). Two experiments, namely trajectory following experiment and the AAN experiment were carried out to evaluate the performance of seamless adaptive AAN control scheme. It was found that the robotic orthosis is capable of guiding the subjects' limbs on reference trajectories during the trajectory following experiment. Also, a variation in robotic assistance was recorded during the AAN experiment based on the voluntary participation of human subjects. This work is an advance on the current state of the art in the compliant actuation of robotic gait rehabilitation orthoses in the context of seamless AAN gait training.

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Section: Assist-as-needed Control Of An Intrinsically Compliant Robotmentioning

confidence: 99%

Assist-as-Needed Control of an Intrinsically Compliant Robotic Gait Training Orthosis

Hussain

Jamwal

Ghayesh

et al. 2017

IEEE Trans. Ind. Electron.

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“…However, the performance of the proposed controller is limited in real applications since the controller gains cannot be freely increased due to practical limitations, such as sampling time, noise and high frequency dynamics. To improve the robustness and performance of the real force control implementations, Disturbance Observer (DOb) was first applied to an SEA by Kong et al [24]. The robust force controller was also similarly applied to the University of Texas's SEA (UT-SEA) and Valkyrie in [18,25].…”

Section: Introductionmentioning

confidence: 99%

A robust force controller design for series elastic actuators

Sarıyıldız

Huang

2017

2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

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A Series Elastic Actuator (SEA) is designed by placing a passive compliant element between a conventional stiff actuator and link. The intrinsically compliant mechanical structure provides several superiorities, e.g., safety, energy efficiency, high force fidelity, low cost force measurement, high transparency, etc., in advanced robot applications, such as humanoids, quadrupeds and exoskeletons. However, the motion control problem of an SEA is more complicated than that of a conventional stiff actuator due to its higher order dynamics. This paper proposes a novel Active Disturbance Rejection (ADR) based robust force controller for SEAs by combining Differential Flatness (DF) and Disturbance Observer (DOb) in state space. The robust state and control input references are systematically generated in terms of a fictitious variable, namely differentially flat output, estimated disturbances and their successive derivatives. A second order DOb is designed in state space so that disturbances and their first and second order derivatives are estimated. It is experimentally shown that high performance force control applications can be performed without requiring the precise dynamic models of the actuator and environment when the proposed robust force controller is implemented. This conference paper is available at Research Online: http://ro.uow.edu.au/eispapers1/1197  Abstract-A Series Elastic Actuator (SEA) is designed by placing a passive compliant element between a conventional stiff actuator and link. The intrinsically compliant mechanical structure provides several superiorities, e.g., safety, energy efficiency, high force fidelity, low cost force measurement, high transparency, etc., in advanced robot applications, such as humanoids, quadrupeds and exoskeletons. However, the motion control problem of an SEA is more complicated than that of a conventional stiff actuator due to its higher order dynamics. This paper proposes a novel Active Disturbance Rejection (ADR) based robust force controller for SEAs by combining Differential Flatness (DF) and Disturbance Observer (DOb) in state space. The robust state and control input references are systematically generated in terms of a fictitious variable, namely differentially flat output, estimated disturbances and their successive derivatives. A second order DOb is designed in state space so that disturbances and their first and second order derivatives are estimated. It is experimentally shown that high performance force control applications can be performed without requiring the precise dynamic models of the actuator and environment when the proposed robust force controller is implemented.

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“…In [31][32][33], the authors use off-the-shelf components for designing SEAs which is an important strategy to keep the costs low. The authors use a planetary gearbox for speed reduction in their designs.…”

Section: Introductionmentioning

confidence: 99%

Re-Engineering a High Performance Electrical Series Elastic Actuator for Low-Cost Industrial Applications

Isik

et al. 2017

Actuators

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Abstract:Cost is an important consideration when transferring a technology from research to industrial and educational use. In this paper, we introduce the design of an industrial grade series elastic actuator (SEA) performed via re-engineering a research grade version of it. Cost-constrained design requires careful consideration of the key performance parameters for an optimal performance-to-cost component selection. To optimize the performance of the new design, we started by matching the capabilities of a high-performance SEA while cutting down its production cost significantly. Our posit was that performing a re-engineering design process on an existing high-end device will significantly reduce the cost without compromising the performance drastically. As a case study of design for manufacturability, we selected the University of Texas Series Elastic Actuator (UT-SEA), a high-performance SEA, for its high power density, compact design, high efficiency and high speed properties. We partnered with an industrial corporation in China to research the best pricing options and to exploit the retail and production facilities provided by the Shenzhen region. We succeeded in producing a low-cost industrial grade actuator at one-third of the cost of the original device by re-engineering the UT-SEA with commercial off-the-shelf components and reducing the number of custom-made parts. Subsequently, we conducted performance tests to demonstrate that the re-engineered product achieves the same high-performance specifications found in the original device. With this paper, we aim to raise awareness in the robotics community on the possibility of low-cost realization of low-volume, high performance, industrial grade research and education hardware.

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Control of Rotary Series Elastic Actuator for Ideal Force-Mode Actuation in Human–Robot Interaction Applications

Cited by 373 publications

References 23 publications

Assist-as-Needed Control of an Intrinsically Compliant Robotic Gait Training Orthosis

Assist-as-Needed Control of an Intrinsically Compliant Robotic Gait Training Orthosis

A robust force controller design for series elastic actuators

Re-Engineering a High Performance Electrical Series Elastic Actuator for Low-Cost Industrial Applications

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